The activity of an aircraft crew consists mainly in:                Piloting the aircraft while the whole time remaining in the flight domain envisaged by the constructor. The flight conditions are in general of fly-by-sight or “VFR” type, the acronym standing for the expression “Visual Flight Rules”. The pilot takes his visual references on the landscape and there are no particular problems. When the situation is degraded through impaired weather conditions for example through reduced visibility (mist or untimely fog, flights at twilight or at night etc.) and/or by untimely movements of the craft related to the wind, to turbulence near the relief or near water etc., or more generally when the pilot undergoes spatial disorientation, he is compelled to direct his gaze into the cabin to pilot with the instruments. In this case he uses known gyroscopic means (artificial horizon, directional gyrocompass, etc.). The use of these means demands very good training and in certain cases may be rendered very difficult because of the dizziness and sensory illusions felt by the pilot, which are in contradiction with the instruments.        Monitoring the exterior environment to take into account certain types of threats which may lead to tricky and/or catastrophic situations. Among the types of threats, may be cited for example:        an encounter with another aircraft which is a risk that must be detected very early so as to be able to engage an avoidance maneuver in complete safety;        an encounter with a terrain (mountains, etc.) and/or artificial obstacles (antennas, wind turbines, etc.) which is a relatively common risk in view of the low altitude of missions;        the departure of a missile coming from a certain direction.        
In flight conditions of fly-by-sight (VFR) and/or fly-by-instruments or “IFR” type, the acronym standing for the expression “Instrument Flight Rules”, the single pilot (and/or the twin crew) must at any moment know where he is with respect to the threats of terrain type as well as to other aircraft. The aircraft may be equipped with systems of “Terrain Avoidance Warning System (TAWS)” type as well as systems of “Traffic Collision Avoidance System (TCAS)” type. These systems are independent and provide specific visual information on dedicated screens as well as audible alarms. The pilot must summarize the information, adopt a tactic in real time and act on the piloting.                Training to learn to manage particular missions with severe constraints. Flight simulators are often used for training and practicing skills on airliners. Their performance level is very often significant. For helicopters, despite considerable progress, it is still impossible to use this type of simulator in an effective manner within the framework of certain specific missions and/or certain flight phases; nothing can replace practical experience. Moreover the level of noise and vibrations of the machine, the variety of missions (in the sense of the terrain and weather) as well as the very nature of the work (cooperation with several people synchronized by means of verbal dialogue) require very regular practical training. The following mission types may for example be cited:                    the winching of an injured individual while hovering which requires good management of height relative to the ground or to the water as well as good coordination of the pilot with the manager of the winch;            the transport of external loads in dangerous zones (mountainous, etc.).                        Being coached by an instructor to learn to:                    interpret the interior and exterior environment during particular missions with severe constraints;            properly manage dialogue and task's partitioning between a twin crew.                        
Finally, whether involving these piloting, monitoring, training and/or coaching missions, and although today's aircraft are more stable and less noisy than in the past, the reading of the instruments (which is not always easy for the pilot) and fatigue may impede the pilot in concentrating on very precise piloting. Hence the existence of devices for assisting the pilot: but they are essentially based on utilizing human visual and/or auditory faculties.
Consequently, to date there is still a need for a system making it possible to improve pilot assistance.